1. Gibbs, J.: The collected works, vol. 1. Thermodynamics. Yale University Press, Yale (1948)
2. Caratheodory, C.: (1995) Untersuchungen uber die Grundlagen der Thermodynamik, Gesammelte Mathematische Werke, Band 2 (Munich)
3. Hermann, R.: Geometry, Physics and Systems. Marcel Dekker, New York (1973)
4. Mrugala, R.: Rep. Math. Phys. 14, 419 (1978)
5. Mrugala, R.: Submanifolds in the thermodynamic phase space. Rep. Math. Phys. 21, 197 (1985)